Hydrocarbon source rock potential and paleoecological studies of the Surma sediments of Manipur region, India: Insights from palynology and organic geochemistry

[Display omitted] •The recovered palynological assemblages indicate a tropical-subtropical climate with the humid condition.•The δ13C values of the organic matter are indicative of C3 vegetation.•The studied Surma sediments are a mixture of types III and IV with a poor gas potential. The palynological assemblages, organic content, Rock-Eval analysis and stable isotope ratios of three outcrop sections were studied of the Miocene Surma Group in Indo-Myanmar Range to characterize the lithology, and assess kerogen types. The well-preserved palynological assemblages from the ATF, AAN and AAS sections indicate a tropical-subtropical climate with humid conditions. The δ13C values of the organic matter in these sections ranges from −19.92 to −26.08 ‰, indicative of C3 vegetation. Among these sections, our data indicates ATF has the driest and AAN wettest climate. Results from Rock-Eval analysis suggests that all the rock samples have poor organic richness (TOC